Really anything that gets your blood circulating and your heart rate up a little followed by stretching strectching
Never strectch cold muscles as they warm they become more pliable ( like most things ) so your less likely to pull or tear something i find doing a basic yoga tape (about 10 or 15 mins they have basic yoga dvds that come in 3 10-min. sessions think its called "10 minute solution they also have many other activites) after a quick warm up has helped alot with my range of motion ( when i actually bother to do it) i think jumping jacks (assuming you don’t have bad knees ect ) is one of the fastest ways to warm up and use arms/legs

I think having some great music to warm up/stretch to will def. motivate me https://www.studioveena.com/img/smilies/icon_sunny.gif